Without wanting to sound too obvious, <Quick Settings>/<Network>/<Ethernet> Turn DHCP off and enter static IP address details.
In order to use your own DNS you need to set a static IP - be sure the IP address you choose isn't being used by any other device and it should also not be in the DHCP range - you should find this in your router settings. Again, not wanting to sound too obvious, but make sure it's in the right subnet Obviously the gateway (or "Gatway" as spelled in the menu!!) will be the IP address of the router, subnet mask presumably 255.255.255.0 and I'd set the DNS to 8.8.8.8 (google) to test, then change to your preferred DNS as required. Other than that, as long as the ethernet cable is good, there's not much else to go wrong
How do you change the DNS for a WiFi connection? Nevermind. I think I found an answer in another thread.
It keeps acting up. My older router (newer one is having an issue at the moment) apparently stops sending the DNS after some period of time and I have to reset it to get the Zidoo to see the Internet. Sadly, the Zidoo has no manual DNS setting for Wi-Fi, just Ethernet so other than getting a different router, there doesn't seem to be a workaround. I have no idea why they didn't include a manual DNS setting for Wi-Wifi, but it's quite irritating as it would have solved the issue without resorting to buying more hardware right now.